/*
 ** A simple and fast generic string hasher based on Peter K. Pearson's
 ** article in CACM 33-6, pp. 677.
 */
#define EDIT_SOURCE
#define NO_SOCKETS
#define NO_OPCODES

#include "std.h"
#include "hash.h"

static int T[] = { 1, 87, 49, 12, 176, 178, 102, 166, 121, 193, 6, 84, 249, 230,
        44, 163, 14, 197, 213, 181, 161, 85, 218, 80, 64, 239, 24, 226, 236,
        142, 38, 200, 110, 177, 104, 103, 141, 253, 255, 50, 77, 101, 81, 18,
        45, 96, 31, 222, 25, 107, 190, 70, 86, 237, 240, 34, 72, 242, 20, 214,
        244, 227, 149, 235, 97, 234, 57, 22, 60, 250, 82, 175, 208, 5, 127, 199,
        111, 62, 135, 248, 174, 169, 211, 58, 66, 154, 106, 195, 245, 171, 17,
        187, 182, 179, 0, 243, 132, 56, 148, 75, 128, 133, 158, 100, 130, 126,
        91, 13, 153, 246, 216, 219, 119, 68, 223, 78, 83, 88, 201, 99, 122, 11,
        92, 32, 136, 114, 52, 10, 138, 30, 48, 183, 156, 35, 61, 26, 143, 74,
        251, 94, 129, 162, 63, 152, 170, 7, 115, 167, 241, 206, 3, 150, 55, 59,
        151, 220, 90, 53, 23, 131, 125, 173, 15, 238, 79, 95, 89, 16, 105, 137,
        225, 224, 217, 160, 37, 123, 118, 73, 2, 157, 46, 116, 9, 145, 134, 228,
        207, 212, 202, 215, 69, 229, 27, 188, 67, 124, 168, 252, 42, 4, 29, 108,
        21, 247, 19, 205, 39, 203, 233, 40, 186, 147, 198, 192, 155, 33, 164,
        191, 98, 204, 165, 180, 117, 76, 140, 36, 210, 172, 41, 54, 159, 8, 185,
        232, 113, 196, 231, 47, 146, 120, 51, 65, 28, 144, 254, 221, 93, 189,
        194, 139, 112, 43, 71, 109, 184, 209, };

INLINE int hashstr(char * s, /* string to hash */
int maxn, /* maximum number of chars to consider */
int hashs)
{
	register unsigned int h;
	register unsigned char *p;

	h = (unsigned char) *s;
	if (h)
	{
		if (hashs > 256)
		{
			register int oh = T[(unsigned char) *s];

			for (p = (unsigned char *) s + 1;
			        *p && p <= (unsigned char *) s + maxn; p++)
			        {
				h = T[h ^ *p];
				oh = T[oh ^ *p];
			}
			h |= (oh << 8);
		}
		else
			for (p = (unsigned char *) s + 1;
			        *p && p <= (unsigned char *) s + maxn; p++)
				h = T[h ^ *p];
	}
	return (int) (h % hashs);
}

/*
 * whashstr is faster than hashstr, but requires an even power-of-2 table size
 * Taken from Amylaars driver.
 */

INLINE int whashstr(char * s, int maxn)
{
	register unsigned char oh, h;
	register unsigned char *p;
	register int i;

	if (!*s)
		return 0;
	p = (unsigned char *) s;
	oh = T[*p];
	h = (*(p++) + 1) & 0xff;
	for (i = maxn - 1; *p && --i >= 0;)
	{
		oh = T[oh ^ *p];
		h = T[h ^ *(p++)];
	}

	return (oh << 8) + h;
}
